Flame-retardant formulations and methods relating thereto

ABSTRACT

Flame retardant formulations comprising boric acid and diammonium phosphate are disclosed herein. Such formulations are in an aqueous form or a powdered form. Methods of generating a flame retardant formulation are also disclosed herein. Such methods comprise combining boric acid and diammonium phosphate in an aqueous solution, wherein the boric acid and the diammonium phosphate is in a ratio range selected from the group consisting of 1:1 to 99:1 and 1:1 to 1:99; and heating the solution until dissolved; thereby generating a flame retardant formulation, wherein the flame retardant formulation consists essentially of boric acid and diammonium phosphate.

RELATED APPLICATIONS

The present application claims priority to the U.S. ProvisionalApplication Ser. No. 61/884,785, filed on Sep. 30, 2013, by Donald S.Sperber and entitled “FLAME-RETARDANT FORMULATIONS AND METHODS RELATINGTHERETO,” the entire disclosure of which is incorporated by referenceherein.

FIELD OF THE INVENTION

The present invention relates to the field of manufacturing flameretardants for treating fires and/or for prevention thereof.

BACKGROUND OF THE DISCLOSURE

Flame retardants are generally well known for the treatment of fires andas a fire prevention tool. They are chemical compounds used inthermosets, textiles and coatings that inhibit or resist the spread offire. Flame retardants are typically added to consumer products to meetflammability standards for furniture, textiles, electronics, andinsulation.

Many combinations of inorganic and organic chemicals such as chlorinatedorganic compounds, amino compounds, asbestos, urea, melamine, antimonytrioxide and mixtures thereof, have been used in flame retardants.However, many of these compounds utilize toxic chemicals such ashalogenated compounds that have negative effects on the environment andhuman health. Indeed, these toxic compounds have been known to degradeover time in the end products in which they've been either integrated inor coated on, emitting toxic gasses that have been linked to severalcancers and neurological diseases. (Roze et al. Environmental HealthPerspectives (December 2009) 117(12): 1953-1958)

Many of the starting chemicals and halogenated compounds used in currentflame retardancy methods require additives in the manufacturing processto neutralize pH. In addition, existing flame retardant formulationstend to impair the integrity of the materials in which they areintegrated in or coated on. Such flame retardant formulations arereadily available in the art. For example, U.S. Pat. No. 6,270,694discloses urea-organic compound-based flame retardants.

The non-toxic flame retardant formulations of the present invention aregenerated by the reaction of boric acid with diammonium phosphate. U.S.Pat. No. 5,082,640 discloses methods of reacting boric acid withdiammonium phosphate for generating luminescent grade boron phosphatefor fluorescent lamp phosphors. However, the methods disclosed require awash step with ammonium hydroxide which washes away excess boric acid.The resulting luminescent grade boron phosphate contains a homogenousmix of equal parts boric acid and diammonium phosphate.

Accordingly, these references do not disclose the embodiments of thepresent invention.

Therefore, a need exists in the art for an improved non-toxic, yeteffective flame retardant formulation. In particular, there exists aneed for an improved method of bringing flame retardancy to productswithout impairing the desired structural integrity of the materialswithin the products. The flame retardants of the present invention offersuch improved flame retardant formulations and methods for bringingflame retardancy to consumer products.

All documents and references cited herein and in the referenced patentdocuments, are hereby incorporated herein by reference.

SUMMARY OF THE INVENTION

The present inventors have developed an improved flame retardantformulation over known flame retardant formulations. The flame retardantformulation disclosed herein comprises a mixture of boric acid anddiammonium phosphate. In certain embodiments, the flame retardantformulation of the invention consists essentially of a mixture of boricacid and diammonium phosphate. In other embodiments, the flame retardantformulation comprises unequal parts of boric acid to diammoniumphosphate. The formulation disclosed herein is a non-toxic flameretardant lacking any halogenated compounds or additives yet issufficiently effective to meet at least the American Society for TestingMaterials (ASTM) Class A Rating and/or equivalent and/or comparableflame spread rating tests. Accordingly, the present invention providesimprovements in starting chemicals, manufacturing, and integration intoend products.

Disclosed herein is a flame retardant formulation comprising boric acidand diammonium phosphate. In certain embodiments, disclosed herein is aflame retardant formulation consisting essentially of boric acid anddiammonium phosphate. In other embodiments, disclosed herein is a flameretardant formulation comprising unequal parts of boric acid todiammonium phosphate.

In addition, disclosed herein is a flame retardant formulationconsisting essentially of boric acid and diammonium phosphate, whereinthe boric acid and the diammonium phosphate are not in equal parts; andwherein the flame retardant formulation is in an aqueous form.

Further, disclosed herein is a flame retardant formulation consistingessentially of boric acid and diammonium phosphate, wherein the boricacid and the diammonium phosphate are not in equal parts; and whereinthe flame retardant formulation is in a powdered form.

In addition, disclosed herein is a flame retardant formulationcomprising boric acid, diammonium phosphate, ammonium sulfate, andmolybdenum. In a further embodiment, the flame retardant formulation isin an aqueous form. In a further embodiment, the flame retardantformulation comprises 20-30% solids in an aqueous solution. In a furtherembodiment, the flame retardant formulation comprises 30% solids in anaqueous solution.

Further disclosed herein is a flame retardant formulation comprisingboric acid, diammonium phosphate, ammonium sulfate, molybdenum,magnesium carbonate, and calcium chloride. In a further embodiment, theflame retardant formulation is in an aqueous form. In a furtherembodiment, the flame retardant formulation comprises a surfactant. In afurther embodiment, the flame retardant formulation comprises liquidlatex. In a further embodiment, the flame retardant formulationcomprises 20-30% solids in an aqueous solution. In a further embodiment,the flame retardant formulation comprises 20% solids in an aqueoussolution.

Also disclosed herein is a method of generating a non-toxic flameretardant formulation comprising: adding boric acid and diammoniumphosphate to an aqueous solution, wherein the boric acid and thediammonium phosphate are in a ratio range selected from the groupconsisting of 1:1 to 99:1 and 1:1 to 1:99; heating the solution untildissolved; thereby generating the non-toxic flame-retardant formulationcomprising a mixture of boric acid and diammonium phosphate. In certainembodiments of the method, boric acid and diammonium phosphate are in aratio range selected from the group consisting of 2:1 to 99:1 and 1:2 to1:99. In another embodiment, the method comprises adding ammoniumsulfate, and molybdenum. In another embodiment, the method comprisesadding ammonium sulfate, molybdenum, magnesium carbonate, and calciumchloride. In another embodiment, the method comprises adding asurfactant. In another embodiment, the method comprises adding liquidlatex. In further embodiment, the method comprises adding 20-30% solidsin an aqueous solution. In a further embodiment, the method comprisesadding 20% solids in an aqueous solution. In a further embodiment, themethod comprises adding 30% solids in an aqueous solution.

In another embodiment, the method of generating a flame retardantformulation further comprises heating the solution to molten.

In a further embodiment, the method of generating a flame retardantformulation comprises combining the flame retardant formulation with abinder or carrier.

In a further embodiment, the method of generating a flame retardantformulation comprises a process of making the flame retardantformulation into a powder, wherein the process is selected from thegroup consisting of drying, grinding, ball milling, wet bead milling,dry bead milling, spray drying, sifting, de-lumping, atomizing, flashdrying, pulverizing, classifying, mixing, and a combination thereof.

In a further embodiment, the method of generating a flame retardantcomprises coating materials with the flame retardant formulation,wherein the materials are natural materials or synthetic materials. Inan even further embodiment, the materials are selected from the groupconsisting of foams, paints, wood, wood composites, and resins.

In other embodiments, the flame retardant formulation and methods ofmaking and using the same in the preceding paragraphs may additionallycomprise silica.

In still other embodiments, the flame retardant formulation and methodsof making and using the same in the preceding paragraphs mayadditionally incorporate any of the preceding or subsequently disclosedembodiments.

The Summary of the Invention is not intended to define the claims nor isit intended to limit the scope of the invention in any manner.

Other features and advantages of the invention will be apparent from thefollowing Drawings, Detailed Description, and the Claims.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention is intended to cover any and all modifications,alternatives, and equivalents falling within the spirit and scope of theinvention.

Unless otherwise defined, all technical terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich this technology belongs.

Flame retardants are used to treat fires or as a preventative measurefor providing flammable components with a level of flame retardancy.Flame retardants are typically coated onto or incorporated into naturalor synthetic materials such as, but not limited to, foam, paints,rubber, resins, wood, and wood composites. Flame retardant products madefrom these materials find many uses in the field such as, withoutlimitation, in building construction, insulation, sound proofing,cushioning, decor, furniture, upholstery, coatings, paints, stains,boating, automobile parts, and air travel.

The flame retardant formulation disclosed herein comprises boric acidand diammonium phosphate. In one embodiment, the flame retardantformulation consists essentially of boric acid and diammonium phosphate.In one embodiment, the flame retardant formulation consists essentiallyof boric acid and diammonium phosphate, wherein the boric acid and thediammonium phosphate are not in equal parts. The flame retardantformulation is in either an aqueous form or a powdered form. This typeof a formulation would find use as a treatment for existing fires and/oras a preventative application. The flame retardant formulation can becombined with a binder or carrier to generate a waterproof flameretardant to apply by coating or spraying to existing surfaces and/or todirectly incorporate into materials and/or consumer products.

Boric acid is well known and readily available to the skilled artisan.Boric acid is a weak acid of boron and has the chemical formula H₃BO₃(sometimes written B(OH)₃) and exists in the form of colorless crystalsor white powder that dissolves in water.

Likewise, diammonium phosphate (DAP), also known as ammonium phosphatedibasic, is well known and readily available to the skilled artisan.Diammonium phosphate has the chemical formula (NH₄)₂HPO₄ is one of aseries of water-soluble ammonium phosphate salts that can be producedwhen ammonia reacts with phosphoric acid.

Chemical entities and/or compounds such as ammonium sulfate, molybdenum,magnesium carbonate, calcium chloride, and silica are readily availableand known in the art. For example, ammonium sulfate, (NH₄)₂SO₄, is aninorganic salt comprising 21% nitrogen as ammonium cations and 24%sulfur as sulfate anions. Molybdenum, ₄₂Mo, is a Group 6 chemicalelement, a free element, occurring in various oxidation states inminerals as a silvery metal with a gray cast. Magnesium carbonate,MgCO₃, is an inorganic salt that is a white solid existing in severalhydrated and basic forms. Calcium chloride, CaCl₂, is a salt of calciumand chlorine and behaves as a typical ionic halide. Silica, also knownas silicon dioxide is a chemical compound that is an oxide of siliconmost commonly found in nature as sand or quarts as well as in cell wallsof diatoms.

In certain embodiments, the flame retardant formulation disclosed hereincomprises boric acid, diammonium phosphate and a chemical compound orentity selected from the group consisting of ammonium sulfate,molybdenum, magnesium carbonate, calcium chloride and a combinationthereof. In a further embodiment, the flame retardant formulation is inan aqueous form. In a further embodiment, the flame retardantformulation comprises 20-30% solids in an aqueous solution. In a furtherembodiment, the flame retardant formulation comprises 30% solids in anaqueous solution. In a further embodiment, the flame retardantformulation comprises 20% solids in an aqueous solution. In a furtherembodiment, the flame retardant formulation comprises a surfactant. In afurther embodiment, the flame retardant formulation comprises liquidlatex. In a further embodiment, the flame retardant formulation maycomprise silica.

The flame retardant formulations of the present invention can becombined effectively with materials, without altering the structuralintegrity of the material and/or resulting product. The amount of theflame retardant formulation necessary in any one application varieswidely depending upon the type of material. For example, with respect tocotton or other natural materials, a very low percentage, such as aminimum of 3%, of the flame retardant formulation may be used incombination with the material. However, the amount of the flameretardant formulation may be as high as 80% in some materials when athermal barrier is desired. In some embodiments, the amount of the flameretardant formulation in a materials application will be in the 5%-25%or the 15%-35% range, particularly when used in combination withsynthetic materials such as foams and/or resins.

The flame retardant formulations disclosed herein are uniquely suited tolessening the compositional requirements in the end products. In thisrespect, the formulations, through their flame retardant synergisticqualities and non-halogenated eco-friendly chemical structures,advantageously preserve the structural integrity of the materials andend products with which they are combined.

The flame retardant formulations of the present invention are producedby chemically reacting boric acid with diammonium phosphate. Methodsdisclosed herein utilize boric acid and diammonium in a 1:1 ratio to99:1 ratio range of either the boric acid or the diammonium phosphate.Flame retardant formulations comprising boric acid and diammoniumphosphate may comprise boric acid that is 1-50% weight percent boricacid and/or diammonium phosphate that is 1-50% weight percent diammoniumphosphate. The boric acid and the diammonium phosphate are mixed andthen heated in an aqueous solution until they dissolve or become molten.The flame retardant product produced by the reaction may then either beused as a flame retardant as-is, or may be combined with a binder orcarrier. The flame retardant may be generated in a powder form. Methodsfor generating flame retardants in a powdered form are well known by theskilled artisan and are readily available in the art. Such methodsinclude, without limitation, drying, grinding, ball milling, wet beadmilling, dry bead milling, spray drying, sifting, de-lumping, atomizing,flash drying, pulverization, classifying, mixing in water (e.g., jet,paddle, shear). The method of the manufacturing process chosen woulddepend on factors such as the type of material and/or product to betreated, how it would be treated, and/or how the resulting treatedproduct will be used.

Additionally, flame retardant formulation methods of the presentinvention may further comprise chemically reacting boric acid anddiammmonium phosphate with a chemical entity or compound selected fromthe group consisting of ammonium sulfate, molybdenum, magnesiumcarbonate, calcium chloride, silica, and a combination thereof. In afurther embodiment, the methods generate a flame retardant formulationin an aqueous form. In a further embodiment, the flame retardantformulation methods comprise adding and/or reacting 20-30% solids in anaqueous solution. In a further embodiment, the flame retardantformulation methods comprise adding and/or reacting 30% solids in anaqueous solution. In a further embodiment, the flame retardantformulation methods comprise adding and/or reacting 20% solids in anaqueous solution. In a further embodiment, the flame retardantformulation methods comprise adding a surfactant such as, withoutlimitation, adding a surfactant that is 1-15% weight percent surfactant.In a further embodiment, the flame retardant formulation methodscomprise the addition of liquid latex such as, without limitation,adding liquid latex that is 5-40% weight percent liquid latex.

The flame retardant formulations and methods of making thereof maycomprise the use of chemically reacting boric acid and diammoniumphosphate with a chemical entity or compound selected from the groupconsisting of ammonium sulfate, molybdenum, magnesium carbonate, calciumchloride, silica, and a combination thereof; wherein, the boric acid is1-30% weight percent boric acid and/or the diammonium phosphate is 1-30%weight percent diammonium phosphate and/or the ammonium sulfate is 1-30%weight percent ammonium sulfate and/or the molybdenum is 1-15% weightpercent molybdenum and/or the magnesium carbonate is 1-15% weightpercent magnesium carbonate and/or the calcium chloride is 1-30% weightpercent calcium chloride.

The methods disclosed herein may additionally utilize silica in theprocess of flame retardant formulation and/or the use thereof. Silicamay be added to a dry or powered form of a flame retardant formulation,i.e., as a flow agent; and/or may be added to any formulation as neededto enhance the properties of the flame retardant, and/or to facilitatethe application of the flame retardant formulation to a material ormaterials.

The flame retardant formulation of the present invention is applied to,mixed into, and/or reacted with a material by incorporating it into thechemistry of a product. When the treated product is subjected to aflame, this produces an intumescent reaction that prevents the flamefrom spreading. Intumescence refers to the process when a flameretardant swells and forms multi-layer char foam in response to theexposure to heat.

The flame retardant formulation of the present invention is directlyadded to and/or used to coat foams, paints, wood, wood composites,resins, or any natural or synthetic material at any suitable temperatureor pressure. This can be performed at any stage of generating thetreated material. This can also be performed in any form of the flameretardant such as, but not limited to, liquid, powder, molten, with abinder or carrier, and any combination thereof. With respect to paints,the flame retardant may be added during the mixing process prior tousing the paint for its end purpose.

The flame retardant formulations and methods of making and using thereofdisclosed herein may incorporate reasonable design parameters, features,modifications, advantages, and variations that are readily apparent tothose skilled in the art in the field.

EXAMPLES Example 1

An aqueous mixture of 40 weight percent boric acid and 40 weight percentdiammonium phosphate was heated and mixed until boiling. When themixture reacted and developed into a molten state, it was poured offuntil cool. It was then dried, ground, and sifted through a 420 meshscreen. The resulting formulation had a pH of about 7.0.

The fire retardant formulation was dried and added to a polyester boatresin that used a methyl ethyl ketone peroxide (MEKP) hardening systemto thermal cure the product. The two different percentages of the fireretardant formulation tested were 20% and 25%. The thoroughly mixedresin and fire retardant were poured into a 1.5×3.0 inch mold and driedto a thickness of approximately 0.25 inches. Once dried and cured it wascut into three test sample pieces. The test sample pieces were sanded toremove the waxy material which formed at the top as it dried. The firetesting was done using a BernzOmatic® torch held in a support apparatusapproximately 0.25 inches away from the test piece. The burn time was 15seconds. Weather conditions were 74 degrees Fahrenheit and 70% humidity.The results are shown in the following Table:

TABLE 1 Breakdown of 20% Testing with Polyester Boat Resin 1^(st) BurnTest 1 min 30 sec 2^(nd) Burn Test 0 min 2 sec 3^(rd) Burn Test 2 min 6sec Average 1 min 2 sec Breakdown of 25% Testing with Polyester BoatResin 1^(st) Burn Test 0 min 1 sec 2^(nd) Burn Test 1 min 17 sec 3^(rd)Burn Test 0 min 1 sec Average 0 min 26 sec

Accordingly, the data show that the fire retardant composition iscapable of extinguishing fire propagation when mixed with one of themost flammable materials known, polyester boat resin.

Example 2

An aqueous mixture of 3 weight percent boric acid, 14 weight percentdiammonium phosphate, 13 weight percent ammonium sulfate, and less than1 weight percent molybdenum was heated and mixed well before and duringboiling until mixture was fully dissolved in solution. The resultingformulation had a pH of about 7.0 and a specific gravity of about 1.18.The formulation had a clear liquid appearance and a slight odor.

The fire retardant formulation was then diluted with water by about 2.5times solution weight. A piece of cotton duck was saturated completelyand drained to an approximate weight gain of about 2.35 times drymaterial weight. The dry cotton duck had a weight gain of about 5% oncedried.

The cotton duck material made according to the above guidelines was sentto a certified testing lab where it passed the Small Scale VerticalFlammability Test for Treated Cotton Fabric; California Fire MarshalTitle 19 1237.1 Small Scale.

Example 3

Step 1: An aqueous mixture of 2 weight percent boric acid, 7 weightpercent diammonium phosphate, 7 weight percent ammonium sulfate, 2weight percent molybdenum, 1 weight percent magnesium carbonate, and 3weight percent calcium chloride was heated and mixed well before andduring boiling until mixture was fully dissolved in solution.

Step 2: An aqueous mixture of 30 weight percent liquid latex and 2weight percent surfactant was mixed together well and combined with theresulting solution from Step 1.

The resulting formulation from the combination of the solutions fromStep 1 and Step 2 has a pH of about 7.0 and a specific gravity of about1.10. The flame retardant formulation had a milky white appearance and aslight odor.

The fire retardant formulation made according to the above guidelineswas used in straight solution to impregnate a piece of polyurethanecushion foam measuring 4″×6″×2″ thickness. The foam was impregnated at6.5 times the weight of the foam and then oven dried. The dry materialweight gain was about 100%. Once dried and cured, the foam had goodresilience and was not hygroscopic.

The foam test sample piece was then fire tested with a propane torch.The torch was adjusted fully open, reaching temperatures of about 3,500degrees Fahrenheit and was held directly on or inches away during thetesting, trying to burn or ignite the foam for about 5 minutes. The foamcharred but did not burn. After the char was scraped off, it wasrevealed that the foam underneath was untouched showing that the foamtest sample was fully fire retarded.

Without departing from the scope and spirit of the present invention,reasonable features, modifications, advantages, and design variations ofthe claimed flame retardant formulations and methods will become readilyapparent to those skilled in the art by following the guidelines setforth in the preceding detailed description and embodiments.

What is claimed is:
 1. A flame retardant formulation comprising boricacid and diammonium phosphate.
 2. A flame retardant formulationconsisting essentially of boric acid and diammonium phosphate.
 3. Aflame retardant formulation comprising boric acid and diammoniumphosphate, wherein the boric acid and diammonmium phosphate are inunequal parts.
 4. A flame retardant formulation consisting essentiallyof boric acid and diammonium phosphate, wherein the boric acid and thediammonium phosphate are not in equal parts; and wherein the flameretardant formulation is in an aqueous form.
 5. A flame retardantformulation consisting essentially of boric acid and diammoniumphosphate, wherein the boric acid and the diammonium phosphate are notin equal parts; and wherein the flame retardant formulation is in apowdered form.
 6. A method of generating a non-toxic flame retardantformulation comprising: a. combining boric acid and diammonium phosphatein an aqueous solution, wherein the boric acid and the diammoniumphosphate are in a ratio range selected from the group consisting of 1:1to 99:1 and 1:1 to 1:99; and b. heating the solution until dissolved;thereby generating a flame retardant formulation, wherein the flameretardant formulation consists essentially of boric acid and diammoniumphosphate.
 7. The method of claim 6, further comprising heating theaqueous solution to molten.
 8. The method of claim 6, further comprisingcombining the flame retardant formulation with a binder or carrier. 9.The method of claim 6, further comprising a process of making the flameretardant formulation into a powder, wherein the process is selectedfrom the group consisting of drying, grinding, ball milling, wet beadmilling, dry bead milling, spray drying, sifting, de-lumping, atomizing,flash drying, pulverizing, classifying, mixing, and a combinationthereof.
 10. The method of claim 6, further comprising coating materialswith the flame retardant formulation, wherein the materials are naturalmaterials or synthetic materials.
 11. The method of claim 10, whereinthe materials are selected from the group consisting of foams, paints,wood, wood composites, and resins.
 12. The method of claim 6, furthercombining boric acid and diammonium phosphate with a chemical entity orcompound selected from the group consisting of ammonium sulfate,molybdenum, magnesium carbonate, calcium chloride, silica, and acombination thereof.
 13. A flame retardant formulation comprising boricacid and diammonium phosphate and a chemical entity or compound selectedfrom the group consisting of ammonium sulfate, molybdenum, magnesiumcarbonate, calcium chloride, liquid latex, surfactant, silica, and acombination thereof.